Hydraulic pump



E. M. PFAusER HYDRAULIC PUMP Nov. 29, 1938.

' Filed March 11, 1936 Sheets-Sheet 1.

. fiw w w x w%.D 4T M i J mw a v. 6 m w w 2 m J 9 Patented Nov. 29, 1938 UNITED STATES PATENT OFFICE HYDRAULIC PUlVIP 7 Edward M. Pfauser, Elm Grove, Wia, assignor to Blackhawk Mfg. 00., Milwaukee, Wis., a corporation of Wisconsin Application March 11, 1936, Serial N0. 68,243'

13 Claims.

retaining to alarge degree a simplified and easi- 1y assembled construction.

In this connection, I prefer to employ a multiple plunger type of pump with each of the plungers being progressively depressed by means of a wobble plate, and being returned automatically by means of springs. The 'wobble plate is carried on a rotatable shaft preferably driven by an electric motor, gas or steam .engine, or any similar power drive.

Another object of the present invention is the provision of positively operating inlet valves, actuated by cammlng means carried by the drive shaft mechanism for the wobble plate, which are automatically closed by spring pressure. In connection with this feature, I provide for synchronizing the action of the wobble plate and the inlet valve, thereby positively eliminating any time lag which might be introduced if the valves are operated solely by suction from the cylinder carrying the plunger.

Still another advantage provided by the present invention is the provision of the intake port of the pump in such position that lubrication of the pump operating mechanism is effected by the oil passing through the pump and being discharged therefrom under pressure.

I also provide for positioning the inlet valve leading to the pump cylinder closely adjacent the end of this cylinder, whereby the suction produced in the cylinder is substantially immediately effective to draw oil thereinto. The discharge valves of the pump cylinders are located immediately adjacent the inlet valve,

whereby the 011 not discharged at each stroke ing means, such as a driving motor frame 4 Another feature of the present construction is the axial disposition of both the inlet and outlet valves in the pump casing, whereby upon removal of the end cap of the housing access may be had to all of these valves for adjustment, replacement or repair.

Other objects and advantages of the present invention will appearmore fully from the following detailed description, which, taken in conjunction with the accompanyingdrawings, will disclose to those skilled in the art the particular construction and operation of a preferred form of the present invention.

.In the drawings: I

Figure 1 is a sectional view through one form of the present invention;

Figure 2 is a transversesectional view taken substantially on line 22 of Figure 1;

Figure 3 is a perspective view of the actuating member for the inlet valves of the pump; and

Figure 4 is a view corresponding to Figure 1 Showing a modified form of pump construction.

Referring now in detail to the drawings, the construction shown in Figure 1 comprises a pump housing 5, which is provided at one end with an outwardly extending flange 6 having suitable openings I adapted to receive securing means for attaching the housing to a suitable supportv or the like.

- The flanged end of the housing 5 is provided with an axially extending recess adapted to receive the packing 8, which packing extends about the drive shaft 9, and is held in position within the recess by means of the packing gland nut l0; threaded into the recess as shown.

The drive shaft 9 is provided with a reduced portion l2, about which is mounted the wobble plate actuating mechanism l3, comprising the tumbler disc portion M, which rides upon suitable ball bearing members I5 and I8, the ball bearings I5 being supported in the outer ball bearing race II which is mounted in the bottom of the open and I8 of the housing 5. The ball bearings H; are confined in position on the camming side of the tumbler disc by means of the ball bearing thrust plate I9, which in turn is held in position by engagement with the pump plungers.

The wobble plate mechanism [3 is secured to the reduced portion of the shaft 9 by the internally threaded portion, which threads over the extending threaded stud 22 formed integral with the shaft 9." The member [3 is also provided with the cylindrical portion 2a. which the'connection between housing 5 and the barrel As shown in Figure 2, the plunger barrel is of internal spider shaped formation, having a plurality of radially extending portions 36 which are adapted to form cylindrical housings for receiving the plungers 32. The plungers 32 are normally urged outwardly of the housing by means of the helically coiled spring members 33 biased between the annular groove 34 formed in the head end of the plunger barrel and the underside of the head portion 35 of the plunger. The recess 24 of the plunger barrel 25, which receives the end 23 of-the tumbler member I3, is cylindrical in shape, and provides a suitable end bearing for the portion 23 of the member l3.

A suitable inlet conduit 36, leading from oil supply means or the like, is threaded into a suitable boss 31 formed in the side wall of the plunger barrel 25, for admitting oil into the interior of the plunger barrel and thence into the interior of the housing}.

The barrelmember 25 and the housing 5 form therebetween an inlet chamber, and oil passing into this chamber from the conduit 36 serves to lubricate the bearings l5 and I6, and then is drawn through the axially or helically extending cutout portions 38 of the inner extending end 23 of the member I 3 along the recess 24 to the annular space 39, which annular space communicates with axially extending inlet valve passageways 40.

The passageways 40 extend through the barrel member 25, and at the opposite end are closed by means of the closure plugs 42. These passageways are provided with an enlarged portion carrying the inlet valve actuating plug 43, shown in detail in Figure 3, which comprises a slidable member having its sides slabbed off, as indicated at 44, to allow for passage of oil therepast into the passageway 40, the plug 43 being guided for reciprocatory movement by the corners formed between the slabbed off portions.

The member 43 is also provided with a project- .ing stud portion or pin 45 which engages the ball check valve 46 for positively opening this valve and movingthe valve cage 41 downwardly against the pressure of the spring 43. The valve cage 41 is provided with a' vent passageway 49, as is the usual practice, and upon inward movement of the plunger member 43, the ball member 46 is pressed off of its seat, and oil may flow through the passageway and through the passageway 50 into the lower end of the plunger cylinder,

The camming plate I9 then depresses the plunger against the tension of the spring 33, forcing the oil which has been drawn into the cylinder outwardly therefrom under pressure. This oil under pressure acts against the ball check valve 52', forcing this checkvalve off of its seat against the pressure of spring 53, and allowing oil to flow through the passageway 54 and through the opening 55in the valve retaining cage member 56 outwardly into the discharge chamber 51 formed at the outer end of the barrel 25.

The projecting plunger members 43 are actuated by a cammingsurface 58 formed at the end of the portion 23 of the member I 3, and projecting axially thereof. This camming surface rotates with rotation of the member 13, and successively depresses the plungers 43 for successively opening the valves 45.. The action of the camming means 58 is synchronized with the wobble plate mechanism so that the inlet valves are opened prior to inward movement of the plungers 32, whereby suction of the plunger 32 moving outwardly under the spring pressure causes the liquid to pass through the inlet valve 46 into the plunger chamber. The wobble plate then cams the. plunger inwardly, producing positive displacement of the oil or other fluid outwardly through the ball check valve 52 into the discharge chamber 51. During this camming movement of the plunger the surface 58 has left the corresponding plunger 43 so that the ball check valve 46 is closed by spring pressure, thereby preventing back flow from the passageway 59 through the passageway 40 into the'inlet chamber.

The discharge chamber 51 is formed by the rear wall of the barrel member 25 and the inner surface of a closure member 59,'which 'is provided with a threaded portion indicated at 60 which threads over a projecting annular shoulder formed on the member 25. The closure member 59 is secured in position by means of a suitable wrench' fitting into the spanner openings 62, and suitable gasket means 63 is provided for sealing this discharge chamber against leakage. The oil forced under pressure into this chamber passes outwardly throughthe port 64 and conduit 65 to from the opposite side of the member 25 and forming the passageways 54, for the discharge of the fluid from the pump cylinders, and the third or inner ring of passageways extending entirely through the member 25 and into the opening 24 formed in the inner end thereof for reception of suitable inlet valve means intermediate the ends thereof.

The cross passageway 50 is provided by drilling radially inwardly from the lateral surface of the member 25, between the passageways for the pump plungers, the passageway 54 and the passageway 40. This passageway is then closed at its outer end by means of the threaded plug 66. By reason of the slots 38 cut in the end portion 23 of the member l3, free flow of oil from the conduit 36 through the inlet chamber and through the slots into the annular chamber 39 is provided, from whence this oil is drawn into the pump cylinders through the passageways 40 and 50 upon depression of the corresponding members 43. By the provision of the positively operating inlet valve ,opening means, I provide for eliminating any possible time lag required for building up a 'sumcient suction in the pump cylinder to overcome the spring resistance of the valve 46. The positive opening of this valve assures that the valve will open at the proper moment for supplying the fluid to the pump cylinder. This has been found desirable in high speed multiple plunger pumps of this type.

Referring now to Figure 4, the structure shown in this figure comprises a simplified assembly of the parts, and the elimination of the positive operating means for the inlet valve.

There is provided a valve housing 10, which receives the drive shaft I2 carrying the tumbler disc member I3, this member being threaded over the threaded stud portion I4 of the shaft I2, and keyed in nonrotative position with respect thereto by means of the transverse key I5. The barrel member I6 in this embodiment of the invention is threaded, as indicated at 11, into the open end of the housing 10, against the gasket means I8, to provide an annular inlet chamber I9 between the members 16 and 10. This inlet chamber receives its supply of fluid from the conduit 80 which is threaded into one side wall of the member 16.

The member I6 is provided with an annular ring of inlet passageways 82, which communicate at their inner ends with the annular chamber 83. The chamber 83 receives fluid through the port 84 leading into the inlet chamber 19, whereby fluid from the chamber 19 may be drawn through the port 84 and space 83 into the passageway 82. It will be noted that in this embodiment of the invention the camming means at the end of the member 13 has been omitted, since positive operation of the inlet valves is not required. Also, the inner end of member 13 is mounted in suitable bearings 8!, which obviously can also be employed in the embodiment shown in v Figure 1.

The outer end of the member I6 is threaded as indicated at 85, to receive the substantially hemispherical closure member 86, which is secured thereon against suitable gasket means 81 to form a discharge chamber 88 connected by the conduit 89 to any suitable mechanism operated by the fluid under pressure.

By the elimination of the operating means for the inlet valves, I am enabled to provide a much longer pump plunger for each of the cylinders, the plungers being indicated at 90. Each of the plungers is normally urged outwardly of the corresponding pump cylinder by means of the spring 92, in the manner set forth in connection with Figure l.

At its opposite end, the pump cylinder communicates with the cross passageway 93, which extends radially outwardly from the inlet-valve passageway 82 to the outlet valve passageway 94. This outlet valve passageway 94 is controlled by the ball check valve 95 normally urged into valve closed position by the spring, 96, and held in this position by the end plug member 91, which is centrally apertured at 98 to provide for outward discharge of fluid under pressure from the pump cylinder into the discharge chamber.

The inlet valve passageway 82 is provided with the valve 99, normally urged into valve closed position by the valve cage member I00, which is engaged by the spring member I02. A suitable closure plug I03 serves to close the outer end of each of the passageways 82.

By the provision of the elongated pump plunger 90,.1 provide for additional sealing and to prevent excessive oil by-pass at this point. The

operating stroke of the plunger is substantially the s'ame as the stroke of the plunger shown in the embodiment of the invention disclosed in Figure 1. This stroke may of course be variedby varying the inclination of the tumbler disc.

The construction shown in Figure 4 is not provided with positively opening inlet valves, and the suction within the pump cylinder and the passageway 93 is relied upon to draw the valve 99 from its seat to allow passage of fluid into the pump cylinder from the passageway 82. Upon reverse movement of the'plunger 90, the member 99 is forced onto its seat, and the member 95 is forced away from its seat to allow the fluid under pressure to be discharged through the passageway. 94 and the port 98 into the discharge chamber 88. The other details of the construction are similar to those shown in Figure 1, and

need not be described specifically with respect to this embodiment of the invention.

-motors, and may be so constructed that when the oil delivered by the pump is not being used'for operating the various devices, it can be by-passed and returned to, a reservoir or the like.- To guard against overloading at any time in the line between the pump and reservoir I may provide a spring-loaded by-pass valve 9| in Figure 4 which may be set at any predetermined pressure and operates in a well known manner. This valve may be disposed axially in the housing between two of the passageways 82, or may be disposed coaxially of the member I3, as desired.

It will therefore be apparent that I have provided a multiple plunger type of high speed hydraulic pump, in which the plungers are successively actuated by a rotating wobble plate mechanism to produce the operating strokes for building up the pressure of fluid passing through the pump. The optimum speed of operation of the pump is preferably about 850 R. P. M., although this may of course be varied. The pump is simple in construction, and may be readily assembled at low cost. In addition, the simplified construction insures positive operation and long life, and the relatively simple valve mechanisms are-so arranged as tobe readily accessible for repair or replacement.

I am aware that various modifications and changes in details of the present construction can be made without departing from the scope and spirit of the present invention, and I therefore intend to limit my invention only as defined by the appended claims.

I claim:

1. A hydraulic pump comprising a plurality of circumferentially spaced pump cylinders, a pump plunger in each of said cylinders, said plungers ally of said cylinders to force fluid under pressure outwardly from said cylinders, the latter being disposed about and with axes parallel with respect to the axis of rotation of said wobble plate, circumferentially spaced valve means extending generally parallel with respect to the axis of rotation of said wobble plate and arranged within said ring of cylinders, and cam' means formed integral with said wobble plate for controlling said valve means to admit fluid successively to each of said cylinders prior to actuation of said plungers.

2. In combination, a. pump housing,- a drive shaft mounted for rotation therein, wobble plate mechanism mounted in said housing for conjoint rotation with said shaft, a plunger barrel member secured to said housing and having a plurality of circumferentially spaced pump plungers extending axially thereof, a pluralityof inlet valve members carried by said barrel member and spaced radially inwardly of the respective cyl inders, said inlet valve members being arranged to be shifted axially withrespect to said drive shaft, means on said wobble plate mechanism for progressively actuating each of said plungers, and cam actuated means on the end of said drive shaft for progressively shifting each of said inlet valve members axially.

3. In combination, a pump housing forming an inlet chamber, a drive shaft and wobble plate mechanism mounted for rotation therein, a pump mechanism mounted at one end of said housing and having plunger members actuated by said wobble plate mechanism, inlet and outlet valve means adjacent said plungers and both of said valve means extending axially inwardly from the outer end of said pump mechanism, said inlet valves communicating with said chamber, and an end closure member secured over the outer end of said pump mechanism and forming therewith an outlet chamber communicating with all of said outlet valves and spaced from said inlet chamber by said housing, whereby removal of said closure member provides access to said valve means.

4. In combination, a cup-shaped pump housing having a drive shaft extending axially thereof, a plunger barrel secured in the open end of said housing and having an annular ring of spaced axially extending pump plungers, a wobble plate mechanism carried by said shaft for successively actuating-said plungers, a central recessed boss on said barrel extending toward said housing and forming a guide for the inner end of said drive shaft, axially extending passageways through said barrel having common lateral communication through said recess to the interior of said housing about said shaft for supplying fluid to said plungers, a valve in each of said axial passageways, and means at the inner end of said shaft for actuating said valves.

5. A substantially cylindrical pump housing having an end closure member forming therewith a discharge chamber, a ring of spaced outlet valves directed into said chamber, a ring of inlet valves accessible from said chamber and disposed radially inwardly of said outlet valves, a corresponding ring of axially extending pump cylinders having communication with both said rings of valves, a plunger reclprocatory in each of said cylinders, means at the end of said housing opposite said discharge thamber for successively actuating each of said plungers, and means disposed generally radially inwardly of said last mentioned means for actuating said inlet valves.

6. In combination, a pump housing defining an inlet chamber and closed at one end by a barrel member, said barrel member having a plurality of plunger cylinders, a plurality of plungers in said cylinders extending axially into said chamber, a pair of concentric annular rings of passages in said barrel member having valve means intermediate their ends, each of said passages communicating with the inner ends of the corresponding plunger cylinders, a drive shaft extending into the other end of said housing, wobble plate mechanism carried by said shaft for successively actuating said plungers, and means conjointly rotatable therewith for successively actuating the valve means in one ring .of passages including means for effecting communication radially outwardly of said recess and opening inthe same direction as said recess, plungers in said cylinders normally urged outwardly thereof, an annular ring of passages communicating with the inner ends of said cylinders and opening into the chamber formed at said opposite end of said member, valve means intermediate the ends of each of said passages in each annular ring of passages, wobble plate mechanism successively depressing said plungers and journaled in said recess, and means carried by the journaled end of said mechanism within said recess for successive-' ly actuating the valve of passages.

8. In combination, a substantially cylindrical housing having an intermediate member defining an inlet chamber and an outlet chamber with opposite ends of said housing, a central axial recess in said member at the inlet side thereof, inlet passages extending from the inner end of said recess axially through said member to the outlet side thereof, ball-check valve means intermediate cans in one of said rings the ends of said passages, means'providing com-- munication between the inlet chamber and said passages, means closing the outlet chamber ends of said passages, a plurality of pump cylinders in said member opening toward the inlet side thereof, plungers in said cylinders, wobble plate mechanism in said inlet chamber rotatable to successively depress said plungers, ball-check valves between the inner ends of said,cylinders and the outlet chamber, means journaling said mechanism in said recess,- and normally extending passages between said iniet passages and the inner ends of said cylinders.

9. A multiple plunger type Dump comprising a barrel member having two concentric rings. of generally axially extending openings, said openings extending through said barrel member, a closure member for each end of said barrel member, the radially outer ringv of axial openings serving as pump cylinders, pump plungers disposed in said pump cylinders, one of said closure members serving to define in connection with the barrel member an outlet means disposed in the inner barrel member adjacent the end thereof at said outlet chamber, the outer ends of said p'ump plungers extending out of the barrel member at the other end thereof, the other closure member forming in conjunction with the other end of the barrel member an inlet chamber, a wobble plate rotatably mounted to bear against one wall of said other closure member and operatively connected to successively actuate said pump plungers, and means extending into said inlet chamber and connected with said wobble plate for actuating the same, said valve means being accessible when one of said closure members is removed, and said wobble plate and associated parts being accessible when the other closure member is removed from said barrel member.

openmg' s in the 10. A pump of the multiple plunger type com-' prising a barrel member having a central shaft chamber, valve receiving socket and a ring of axially disposed pump cylinders arranged concentrically about said socket, two sets of generally axially disposed openings in' said barrel member, one set communicating with the inner ends of said pump cylinders and the other set disposed radially inwardly of said first set and extending from said socket toward the outer end of said barrel member and into communication with said pump cylinders, valves in each of said openings controlling the flow of fluid therethrough, pump plungers disposed in said pump cylinders and extending outwardly at the inner end of said barrel member, wobble plate mechanism disposed at the inner end of said barrel member for actuating said pump plungers, a closure member enclosing said wobble plate mechanism and forming in conjunction with said barrel member an inlet chamber with which said socket communicates, shaft means for driving said wobble plate mechanism disposed in said socket, and means providing for a flow of fluid'irom said inlet chamber into the socket and the central openings communicating therewith.

11. A multipleplunger type Dump comprising a barrel member, a central axial recess in one end of said barrel member, an annular ring ofpassages extending axially from said recess to the opposite end of said member, an outer concentric ring of cylinders formed in said member radially outwardly of said recess and opening in the same direction as said recess, plungers therein normally urged outwardly thereof, an annular ring of passages communicating with the inner ends of said cylinders, valve means intermediate the ends oi each of said passages in each annular ring of passages, wobble plate mechanism successively depressing said plungers and journaled in said recess, and means carried by the V Journaled end of said mechanism within said recess for successively actuating the valve means in one of said rings of passages.

12. A multiple plunger type pump comprising a barrel member threaded at one end, a chambar-forming closure member secured to said threaded end, a central axial recess in the threaded end of said barrel member, an annular ring of inlet passages extending axially from said recess toward the opposite end of said member and into communication with said cylinders, an outer concentric ring of cylinders formed in said member radially outwardly of said recess and opening in the same direction as said recess, plungers therein normally urged outwardly thereof, an annular ring of passages communicating with the inner ends of said cylinders, valve means intermediate the ends of each otsaid passages in each annular ring of passages, wobble plate mechanism disposed in the chamber formed by said closure member and journaled in said recess for successively depressing said plungers, and means, carried by the journaled end of said mechanism within said recess for successively actuating the valve means in one of said rings of passages.

13. In combination, a substantially cylindrical housing having an intermediate member defining tween the inner ends of said cylinders and the outer end of said member, means journaling said mechanism in said recess, and passages between said inlet passages and the inner ends of said cylinders.

- EDWARD M. PFAUSER. 

